"You see Vicki?" says Tor, "Not only does the reply have to be true, it has to be the correct answer as well."
To the Moroks, 'truth' and 'the correct answer' are the same thing. And 'correct' means 'official', 'integrated', 'obedient'.
"Do you understand that all questions are to be fully
answered?" asks the computer, "What is your rank? What is your name? Do you have the
Governor's permission to approach? Have you a requisition signed by the
Governor? What is its reference number?"
'Truth' is defined as the correct answer to all these questions, the correct integration into the imperial system, the correct official position. Legality is what power says it is. And only the state, and its functionaries, have the legitimate right to use violence.
"Withdrawal requisition numbers are fed in from headquarters. It
has to tally with the number given," explains Tor.
Systems of oppression run on tallying numbers.
Vicki's response is to rip the front off the machine and start mucking around in its arcane guts.
She reprograms it; forces it to redefine words according to her insurrectionary imperatives.
"What is your name?" it asks.
"For what purpose are the arms needed?"
The machinery, suitably seized and retooled, is satisfied with this. It's the truth... and it's now the 'correct' answer too, now that Vicki has changed its parameters.
Behind the newly-open door, there is the potential to remake the world; the ability to disrupt the imperial state's monopoly on violence.
"There’s everything we need here and more!" declares Sita.
Well, he's wrong about that. They need a lot more than just the ability to shoot people. But it's a start. It's a way of defending their challenge to a system that is ruthless in its determination to hold on to power. And the door itself is perhaps more important even than the guns behind it. They've opened it. They've seized control of the machinery - by redefining truth to mean something more than just the imperial state's idea of 'the correct answer'.